Locking mechanism for a rotary working member

Abstract

An operating ring ( 7 ) is externally fitted, with the ability to rotate, to the main body of the locking nut in between a locking flange ( 3 ) and a flange of the locking nut ( 5 ); ball bearings ( 11 ) are inserted between the operating ring and the locking flange; three or more arc-shaped grooves ( 54 ) are formed—facing toward each other and extending in concentric shapes in the circumferential direction—in the mating surfaces of the flange of the locking nut and the operating ring; locking balls ( 9 ) are accommodated inside the arc-shaped grooves of the flange of the locking nut ( 5 ) and the operating ring which face toward each other; the total dimension—in the axial direction of the rotary drive shaft—of each pair of arc-shaped grooves which accommodate the locking balls ( 9 ) is set smaller than the diameter of a locking ball; and a localized indentation is formed at the bottom surfaces on at least one side of said pair of arc-shaped grooves.

What is claimed is:  
     
       1. Locking mechanism for a rotary working member wherein a working member (D) and a locking flange ( 3 ) are loosely fitted to the small-diameter threaded part of a rotary drive shaft ( 1 ) equipped with a large-diameter part and a small-diameter threaded part, which mechanism is of a type wherein a locking nut ( 5 )—which comprises a main unit and a flange and is screwed to the small-diameter threaded part presses the working member against the end surface of the large-diameter part of the rotary drive shaft via the locking flange, thereby locking the working member to the rotary drive shaft, characterized in that: an operating ring ( 7 ) is externally fitted, with the ability to rotate, to the main body of the locking nut in between the locking flange and the flange of the locking nut; a ball bearing is inserted between the operating ring and the locking flange; three or more arc-shaped grooves are formed—facing toward each other and extending in concentric shapes in the circumferential direction—in the mating surfaces of the flange of the locking nut and the operating ring; locking balls ( 9 ) are accommodated inside the arc-shaped grooves of the flange of the locking nut and the operating ring which face toward each other; each pair of arc-shaped grooves which accommodate the locking balls has a total dimension—in the axial direction of the rotary drive shaft—which is less than the diameter of a locking ball; and a localized indentation is formed at the bottom surfaces on at least one side of the said pairs of arc-shaped grooves. 
     
     
       2. Locking mechanism as claimed in claim  1 , characterized in that the said locking nut and operating ring are elastically forced together so as to wedge the locking balls between the ends of each pair of arc-shaped grooves. 
     
     
       3. Locking mechanism as claimed in claim  2 , characterized in that the forcing means that performs the said elastic forcing together is configured from: an arc-shaped groove formed by gouging the locking nut or the operating flange at the mating surface of these members, a securing pin that projects from the other member into this arc-shaped groove, and a compression spring that is accommodated inside the said arc-shaped groove with one end engaging with the securing pin and the other end in contact with the end of the arc-shaped groove. 
     
     
       4. Locking mechanism as claimed in claim  1 , characterized in that the said working member is disk-shaped.